You are given an m x n
grid. A robot starts at the top-left corner of the grid (0, 0)
and wants to reach the bottom-right corner (m - 1, n - 1)
. The robot can move either right or down at any point in time.
The grid contains a value coins[i][j]
in each cell:
coins[i][j] >= 0
, the robot gains that many coins.coins[i][j] < 0
, the robot encounters a robber, and the robber steals the absolute value of coins[i][j]
coins.The robot has a special ability to neutralize robbers in at most 2 cells on its path, preventing them from stealing coins in those cells.
Note: The robot's total coins can be negative.
Return the maximum profit the robot can gain on the route.
Example 1:
Input: coins = [[0,1,-1],[1,-2,3],[2,-3,4]]
Output: 8
Explanation:
An optimal path for maximum coins is:
(0, 0)
with 0
coins (total coins = 0
).(0, 1)
, gaining 1
coin (total coins = 0 + 1 = 1
).(1, 1)
, where there's a robber stealing 2
coins. The robot uses one neutralization here, avoiding the robbery (total coins = 1
).(1, 2)
, gaining 3
coins (total coins = 1 + 3 = 4
).(2, 2)
, gaining 4
coins (total coins = 4 + 4 = 8
).Example 2:
Input: coins = [[10,10,10],[10,10,10]]
Output: 40
Explanation:
An optimal path for maximum coins is:
(0, 0)
with 10
coins (total coins = 10
).(0, 1)
, gaining 10
coins (total coins = 10 + 10 = 20
).(0, 2)
, gaining another 10
coins (total coins = 20 + 10 = 30
).(1, 2)
, gaining the final 10
coins (total coins = 30 + 10 = 40
).
Constraints:
m == coins.length
n == coins[i].length
1 <= m, n <= 500
-1000 <= coins[i][j] <= 1000